Big Ben is back on the injury list.Making his second start since returning from a knee injury, Roethlisberger injured his left foot midway through the fourth quarter of a 38-35 win against Oakland on Sunday. He was taken to the locker room on a cart and the Steelers announced Roethlisberger eventually left Heinz Field to undergo further evaluation.Steelers coach Mike Tomlin said Roethlisberger needs an MRI and didn't have any further update.Roethlisberger missed four games after he sprained his left knee in Week 3.